High speed tool steel



PatentedMay 23, 1933 UNITED ST TE PATENT OFFICE LEO tween, or Ausram- Assmnoa r oasraaamcmscan scammsrmnwmaxr: A. a, or names, aver-am, m avenues: comm men arm moon sun.

ll'o Drawing. Application filed illoveniber 11, 1839, Serial Io. 408,888, and in Aultria lovember 14, 1888.

So called self hardening: steels for-tools have already been proposed, some of which are tungsten manganese steels free from chromium while othersare tungsten chromium steels, but it has never been proposed to use cobalt as a constituent in allo s of the above com osition. Since in all sel hardenwas comiaraing steels t e cutting capacity tively small, steels containing cobalt an free from chromium and having a highcutting cagecit had still less been proposed.

he own high speed tool steels on the other hand which since the beginning of this century have replaced on account of their high cutting ca acity the self hardening steel,

reviously use have in all cases chromium or their main constituent and for another essential; constituent tun sten' or its equivalents and recently also coba t has been frequentl used for an additional constituent of suc high speed tool steels. 'However, chromium is considered an, essential constituent of all modern high speed tool steels having an adeuate cutting capacity andis used in all cases. hese known steels containin chromium and tungsten with or without t e addition of cobalt ofier difiiculties in connection with ractical use as re ards their being worked 1n the heat, their being shaped in the cold and their thermic treatment.

. Now it has been discovered that the cutting ca acity of high speed tool steels containin co alt without any addition of chromium 1S substantially the same as that of the chromium containing high speed tool steels heretofore used, but the workin in the heat of such cobalt-steelsfree from c romium, their shaping in the cold and their thermic treatment is much more easy and thus the difliculties above referred to met with in the case of chromium containing high speed tool steels are at least tent even entirely removed.

The following figures givevarious examples of carrying my present invention into.

-' may vary within wide limits. Other con- .imation eatly reduced and to'some ex- 7 efl'ect. Especially the contents in the elements, usually accompanying iron, such as manganese and silicon are given by way of examples only and are by no means limitative.

It will be seen that the contents in cobalt 6o stituents of the alloy such for instance as' vanadium molybdenum, tantalum, titanium, uranium and so on are either elements accompanying other constituents of the alloy or ma be added in suitably higher proportions or. special uses of the resulting allo a The advantages secured by the present inventionare obtained to a smaller'extent even in the presence of very'small percentages of chromium, which may be simply considered as impurities.

The steels according to the present invention may be manufactured in various ways well known per se in the manufacture of h speed'tool steelsat I claim is: 1. A substantially chromium free high speed-tool steel comprising in rough approx- Tun ten 16.5-22.50% C(i alt 3.519.00% Vanadium 0.5-1.7 5% Carbon 0.9-1.25% Tantalum -0.1-.2.15% Silicon 0.10.40% Molybdenum 0.11.10% Manganese up to 0.35% and the remainder iron.

2. A substantially chromium free high speed tool steel comprising in rough approximation: I

Tungsten 16.5-22.50% Co alt 3.519.00% Vanadium 0.5-1.7 5%

Carbon 0.91.25% Tantalum (Ll-2.15% Silicon 0.10.40% Molybdenum 0.11.10% Manganese up to 0.35% chromium in traces as impurities, and the remainder iron.

3. A substantially chromium free high speed tool steel comprising in rough approximation:

Iron 65.02% Tungsten 19.82% Cobalt 10.81% Vanadium 1.64%

M01 bdenum 1.06%

arbon"0.97 Manganese 0.35% Tantalum 0.17%

'26 Silicon 0.16%

4:. A substantially chromium free high s'peed tool steel comprising in rough approx-' imation:

e 7 Iron 66.89% A Tungsten 19.33%

Co alt 9.40% Vanadium 1.74% Carbon 1.00% Tantalum 0.81%

I Mol bdenum 0.41%

ilicon 0.27% Y Manganese 0.15% t In testimony whereof I afiixed' my 'signaurea .Lno KLUGER. 

